Yes we certainly need the elon musk version of Jacque Cousteau to invest lots of money into deep sea exploration
That would be great! Unfortunately I think that there is very little to potentially gain from exploring it (in terms of money), so I guess businessmen are less likely to invest in this compared to space travel (which can potentially be worth billions).
If Prof Google serves me well its only less than 5% we have actually explored, so many mnay more decades of exploration to go. Maybe Norway and their seafaring history could set up the first base for aquanauts.
Yeah, most of it is unexplored. I think Norway has plans to actually set up a permanent research ship that will travel around the globe and collect data from the ocean, so we are already working on something like what you suggest :)